Nowadays, the hydraulic brake system for the vehicle can be generally classified into single-cylinder brake systems and dual brake systems. The brake fluid in the conventional piston pressure system in the brake master-cylinder flows to each brake wheel cylinder upon application of the brake pedal. The car will incline forward in conventional systems since the shorter brake tube leading to the front wheel causes a quicker resonse in the front wheel during braking. In an emergency braking situation, vehicle wavering, zig-zagging, and overturning are possible. As far as the conventional single-cylinder brake system is concerned, the vehicle will lose braking function thereby unfavorably and greatly affecting the driving safety thereof when the brake tube is damaged, such as, by a breach and leakage. With regards to the dual brake system, when the brake tube in either brake system is damaged, such as, by breach and leakage, one of the brake systems can still perform the braking function. However, the overlapping pistons in the same master cylinder considerably descrease the pressure for pressing the brake fluid so that the overall brake system cannot entirely develop the proper braking function.